QPolygonF 类提供使用浮点精度的点列表。 更多...
| 头： | #include <QPolygonF> |
| CMake: |
find_package(Qt6 COMPONENTS Gui REQUIRED)
target_link_libraries(mytarget PRIVATE Qt6::Gui) |
| qmake: | QT += gui |
| 继承： | QList |
注意： 此类的所有函数 可重入 .
| QPolygonF (const QPolygon & polygon ) | |
| QPolygonF (const QRectF & rectangle ) | |
| QPolygonF (const QList<QPointF> & points ) | |
| QPolygonF () | |
| QRectF | boundingRect () const |
| bool | containsPoint (const QPointF & point , Qt::FillRule fillRule ) const |
| QPolygonF | intersected (const QPolygonF & r ) const |
| bool | intersects (const QPolygonF & p ) const |
| bool | isClosed () const |
| QPolygonF | subtracted (const QPolygonF & r ) const |
| void | swap (QPolygonF & other ) |
| QPolygon | toPolygon () const |
| void | translate (const QPointF & offset ) |
| void | translate (qreal dx , qreal dy ) |
| QPolygonF | translated (const QPointF & offset ) const |
| QPolygonF | translated (qreal dx , qreal dy ) const |
| QPolygonF | united (const QPolygonF & r ) const |
| QVariant | operator QVariant () const |
| QDataStream & | operator<< (QDataStream & stream , const QPolygonF & polygon ) |
| QDataStream & | operator>> (QDataStream & stream , QPolygonF & polygon ) |
A QPolygonF is a QList < QPointF >. The easiest way to add points to a QPolygonF is to use its streaming operator, as illustrated below:
QPolygonF polygon; polygon << QPointF(10.4, 20.5) << QPointF(20.2, 30.2);
In addition to the functions provided by QList , QPolygonF provides the boundingRect () 和 translate () functions for geometry operations. Use the QTransform::map () function for more general transformations of QPolygonFs.
QPolygonF also provides the isClosed () function to determine whether a polygon's start and end points are the same, and the toPolygon () function returning an integer precision copy of this polygon.
The QPolygonF class is 隐式共享 .
另请参阅 QList , QPolygon ，和 QLineF .
Constructs a float based polygon from the specified integer based polygon .
另请参阅 toPolygon ().
Constructs a closed polygon from the specified rectangle .
The polygon contains the four vertices of the rectangle in clockwise order starting and ending with the top-left vertex.
另请参阅 isClosed ().
Constructs a polygon containing the specified points .
Constructs a polygon with no points.
另请参阅 QList::isEmpty ().
Returns the bounding rectangle of the polygon, or QRectF (0,0,0,0) if the polygon is empty.
另请参阅 QList::isEmpty ().
返回
true
若给定
point
is inside the polygon according to the specified
fillRule
；否则返回
false
.
Returns a polygon which is the intersection of this polygon and r .
Set operations on polygons will treat the polygons as areas. Non-closed polygons will be treated as implicitly closed.
另请参阅 intersects ().
[since 5.10]
bool
QPolygonF::
intersects
(const
QPolygonF
&
p
) const
返回
true
if the current polygon intersects at any point the given polygon
p
。也返回
true
if the current polygon contains or is contained by any part of
p
.
Set operations on polygons will treat the polygons as areas. Non-closed polygons will be treated as implicitly closed.
该函数在 Qt 5.10 引入。
另请参阅 intersected ().
返回
true
if the polygon is closed; otherwise returns
false
.
A polygon is said to be closed if its start point and end point are equal.
另请参阅 QList::first () 和 QList::last ().
Returns a polygon which is r subtracted from this polygon.
Set operations on polygons will treat the polygons as areas. Non-closed polygons will be treated as implicitly closed.
Swaps polygon other with this polygon. This operation is very fast and never fails.
创建并返回 QPolygon by converting each QPointF 到 QPoint .
另请参阅 QPointF::toPoint ().
Translate all points in the polygon by the given offset .
另请参阅 translated ().
这是重载函数。
Translates all points in the polygon by ( dx , dy ).
另请参阅 translated ().
Returns a copy of the polygon that is translated by the given offset .
另请参阅 translate ().
这是重载函数。
Returns a copy of the polygon that is translated by ( dx , dy ).
另请参阅 translate ().
Returns a polygon which is the union of this polygon and r .
Set operations on polygons will treat the polygons as areas. Non-closed polygons will be treated as implicitly closed.
另请参阅 intersected () 和 subtracted ().
Returns the polygon as a QVariant .
写入给定 polygon 到给定 stream ，并返回流引用。
另请参阅 序列化 Qt 数据类型 .
Reads a polygon from the given stream 进给定 polygon ，并返回流引用。
另请参阅 序列化 Qt 数据类型 .